Since cancer is ranked high in causes of death in various countries around the world, early detection and treatment of cancer is desired. Most of death of human beings by cancer is caused by a metastasis and recurrence. A metastasis and recurrence of cancer occur when a cancer cell is fixed on and invade a vessel wall of a tissue of another organ from primary lesion via a blood vessel or a lymph vessel, and form a micrometastasis. Such a cancer cell circulating in the human body via a blood vessel or a lymph vessel is called circulating cancer cells (Circulating Tumor Cells, hereinafter referred to as “CTC” in some cases).
If the presence or absence and the amount of cancer cells in the blood vessel (CTC) which can cause a metastasis and recurrence of cancer can is enabled, great contribution to cancer treatment becomes possible. As a conventional technique for trapping cancer cells in the blood, for example, the constitution described in Patent Literature 1 is known. The technique described in Patent Literature 1 captures cancer cells in the blood by a filter, and the literature shows a manufacturing method using semiconductor technology of the filter, the shape of a cell unit in which the filter is stored, and the structure of a flow pass to let the blood and a treatment liquid flow.